Five element hot-gas motor with means for heating the gas thereof exclusively in theheater element thereof



1950 H. RlNlA ET AL I FIVE ELEMENT HOT-GAS MOTOR wTTH MEANS FOR HEATINGTHE GAS THEREOF EXCLUSIVELY IN THE HEATER ELEMENT THEREOF ZSheets-Sheet1 Filed Aug. 29, 1945 AY KM MM W 7 i m may WFM 5 m H m mm Mm HR A1 H $2QM Dec. 26, 1950 H. RlNlA ET AL 5 5 FIVE ELEMENT HOT-GAS MOTOR WITHMEANS FOR HEATING THE GAS THEREOF EXCLUSIVELY IN THE HEATER ELEMENTTHEREOF Filed Aug. 29, 1945 2 Sheets-Sheet 2 Patented Dec. 26, 1950 FIVEELEMENT HOT-GAS MOTOR WITH MEANS FOR HEATING THE GAS THERE- OFEXCLUSIVELY IN THE HEATER ELE- MENT THEREOF Herre Rinia, Heinrich deBrey, Franciscus Lambertus van Weenen, Ysbrand Boers, Gabriel LeonardSypkens, and Willem Jan van Heeckeren,

Eindhoven, Netherlands, assignors to Hartford National Bank & Trust 00.,Hartford,

Conn., as trustee Application August 29, 1945, Serial No. 613,394 In theNetherlands May 5, 1941 Section 1, Public Law 690, August 8, 1946 Patentexpires May 5, 1961 6 Claims.

In the known hot-gas motors, which also in-,

clude hot-air motors, a certain amount of gas is heated in a closedchamber termed hot chamber. As a result of this heating the pressure ofthe gas increases. This gas with increased pressure flows to a secondchamber, termed cold chamber, which freely communicates with thefirst-mentioned chamber and wherein this gas sets a working piston inmotion, expands and cools down. A second piston, termed displacer,penetrates into the hot chamber to such extent that substantially allthe gas, except that which is contained in the unavoidabledisadvantageous chamber, is driven out of the hot chamber. The gaswhich, after expansion, is contained in the cold chamber may be carriedoff to the outside atmosphere. In this case use is made of air as mediumin the motor. The movement of the displacer out of the hot chamber hasthe effect of sucking a new amount of air into the hot chamber. Motorsof this kind are termed motors with open cycle.

Hot-gas motors are also known in which the gas, after expansion, ismaintained closed up in the cold chamber and cooled down there. In thiscase the gas pressure decreases and the working piston may make theentering stroke. The displacement of the displacer has the effect ofbringing the same amount of gas back to the hot chamber. Motors of thiskind are termed motors with closed cycle.

The present invention solely relates to hot-gas motors with closedcycle, which also include motors in which a certain amount of gas may betaken from the cycle or added thereto, for example to compensate lossesdue to leakage.

With hot-gas motors it is known to arrange a regenerator in the path ofthe gases between the hot and the cold chambers. Part of the heat of theexpanding gases flowing out of the hot chamber is taken up by thisregenerator. During the flowing back of the cooled gases from the coldto the hot chamber this heat is given off to the gases, which results inless heat getting lost through cooling for the working process. With anunvaried amount of heat supplied from the exterior to the motor andunvaried cylinder contents the use of the regenerator consequently hasthe effect of increasing the induced power of the motor. The fixedlosses of the motor, such as radiation, remains substantially unvaried,so that the total efficiency increases.

The power per unit of cylinder contents also increases with a morecomplete heating and cooling of the medium. As a matter of fact, if notall the medium is brought completely heated or cooled into the hot andcold chambers respectively, the cycle is also accomplished by an amountof medium which has not taken up the total available energy andconsequently cannot give oli the largest possible portion of thisenergy. Consequently, in the case of poor cooling and heating largercylinder contents would be required for obtaining a definite power,resulting also in an increase in value of the fixed losses.

In a known hot-gas motor with closed cycle the medium traverses aregenerator from the hot to the cold chamber. The heating and thecooling of the medium is effected in the hot and cold chambersrespectively. Since the gas comes into cont:.ct with the hot and thecooled surfaces only as far as the wall of these chambers is concerned,the gas which is not in the immediate vicinity of the wall will attain asufiicient increase in temperature only if the time available thereforis very long. It would ensu therefrom that the speed of the motor mustbe maintained very low.

For obtaining a definite power it is also possible to use a large amountor" medium with unvaried pressure so that the motor becomes large-sizedand the losses proportionally increase. In order to house a largeramount of medium with unvaried size of the motor, it is also possible toincrease the pressure of the medium. The increase in pressure does notresult in an increase in heat conductivity, but the specific heat doesincrease, so that the conditions for the heattransmission become stillworse.

Hot-gas motors with closed cycle are known which are equipped with a hotchamber, a heater, a regenerator, a cooler and a cold chamber and inwhich the gaseous medium on its way from the hot to the cold chambertraverses the heater, the regenerator and the cooler in this sequenceor, during the movement from the cold to. the hot chamber, in thereversed sequence. In this case, however, there is intermediate theregenerator and the cooler proper a chamber in which the gas strokesalong a heated surface. A cer- 3 tain amount of heat of this heatedsurface is emitted to the gaseous medium, which heat is carried 5 offin::' the cooler immediately following and is -lost'for th workingprocess. Theefdciency of this hot-gas motor is thus highl det- 5 By theterms heater andicooler. we m here members which serve toexchangeh at wth the gaseous medium, the latter over the path of flow being limited byat leasttWQ surfaces exerting' a heating and a cooling action.re'spectiuely on the medium the heat being supplied from and carried onrespectively to the. outside;

By the terms heater and coolerl.-.we may here also mean members whichserve toexchange heat with the gaseous medium, the gaseous current beingsubdiyided'into a large number of at The supply of heat in t able ofcontaining substantially all the medium the contents thus becomedisadvantageous for a rapid and complete heat-transmission.

-The-absence or a heater-and/or cooler detrimentally affects the heatingand the cooling of -,the medium so that the efliciency decreases, as

has .beenexplained in the foregoing.

. he..absence;ol a regenerator not only gives a loss bi heat, as hasbeen explained in the regtiiihg, but-the heater thus also directlyadoins the cooler so that a loss of heat through fcbhdiictio'nfrOni theheater to the cooler is un- "he, interposition of an insulated H, e thisloss may be reduced, it is suits also in an extension of the ya tageous.chamber in the motor. According to the invention, the above-statediitieeelengentsofthe hot-gas motor are constructively arrangedrelatively to each other and to epistonand the displacer of the motor,in such her. at the heater, the regenerator and the comer in thedirection of movement of the pist'o n"and of the displacer are locateddirectly behind each other and about the piston and the dis- "least'five, separateparts; This subdivision-may P Inethis. case the. hea er.,9? 1 ,5

be varied in the-direction of thegaseous current. Theheat-transmissionisimproved by the col- -"lisions produced as aresult-of this subdivision.

{The heat eraswell as'thecooler may have propstru tur oifthc. otas;QtQlT- -T med er'ties 'as mentioned in -theforegoing By'theterms hotchamber and coldchamber"-'we mearrherechambers whose' size during thecycle varies rroni nought to a finite -valuecated.on-.the.zside..iof=;fih b tchamb and the cooler .on the. side..ofthe cold chamber. ,3

The a v nt ned rra e en erm s 9 obtaining-tan; extrem ly ,Simple andcompact t-fiows'. from the hot chamber al n the outside ofothe.displacer.thrqugh the -heat er and the regenaeratonandthe .GD lIaEQ :thfia d. .Q emb riot and.thetcoldlflll mbfi dma3Z'. V! .W b coldportion respectivelyof the medium. The f i fi .i nii li ha911otherchambers of constant volume of'themoj fi e l' dt fidsazMQEfiQVfilIa a?" to -Which contain the medium, are disadvanm s mentoithsihiit tfl e ns fewlfi 1 t chambers, i I u ithcid s ce ofierrqnsiruct sly t e adi ko to ro vide a hot gas motgr .hav.. .=:1 .Yan agQg a ing a closed cycle with a hot-chamber, a regeneoi in of.the ael me trthed mensi n -fi erator," a cooler and a cold chamber, the-medium}Q.t@ti Qrma iqz fi L Q.-P. :9 h 'being-;heated'betiveen the hot chamberand the Q l'ifii' 81 2 1 4 .011 leads to minimum 'regenerator. This iseffected in a channelhavhiss-Q51 031191317. Que. t? 17 1 r '9 ing "only-one-wall which hasheatsupplied to a 11. mvent q 1 m 9 9 3 it-and-yinaddition, is not subdivided so-thatin is ee flet x m 9 :Q tib tlmhfi iml-e he iii ithiscase there question f aflheatevdn and compression in themotor which are advanthe -sense of the presentinvention As it has -3Win; h'hh p m ti alread-ybeen explained in the foregoing thispoor-heating of the medium results in the-en-'-- i t-ae .-n% 99- mb--ergy--per unit of cylinder contents being ex- ISO- 1 U1 QQ. .5 IQ hl 9ie-r isin m trmely,sman p, :hehot.; ;l ian-119er the expanded gasjisconducted To obtain the optimum power per unitof c-yl- -1 i 11Q xh a e?s .t ei-ihaf wdi ali ---inder.contents andin connectiontherewitha the"iflll fid 1133's; h ..expan$ 9a at eas a y 9 -optimum efficiency it isnot sufiicient thatiour spfi fifi i .3dt ly i g f- D out" of five saidelements are present, since each mg the compression cii .43.9? ,q a rlfiinfl deviation from the invention rendersitheener-gy r c-.' .d.:chamb r maybsh g l adbuas per unit of-cylinder contents very small,:which .cqoleuans ase oudc dfihambe i qthatj h 8 --may also result in aconsiderable decrease-in i'icompressediro nfihe;cold chamber may-give fi=efiiciency.- Whereas-the knownghot-gas motorsa-i ';1 e,.he?itnh 0.d1ledduring, Q9 R n fiei -'have an energy per unit of cylindercontentsof a0second.cooler before ,being gompressed, further. about 0.2-0.7 W./cm. itis a surprising fact that Thiscontributesto anisotherrnal compression.inthe motor according to the.invention,- which This invention willbemore-clearly understood consequently comprises the above-statedfive-.-.:by.,rei6rence-.:t0 ,the, accompanying drawings elements, the energyper unit of cylinder con--- ishowing by way'of example, a fewembodiments tents comparable with these valueslies at 3.5 thereof...

i. W./cm. and-even much higher, for example '7 Fig. .llshowsinpartschematically a; hot-gas W./cm. as has been found by experiments. otoraccording to the invention in longitudinal Consequently, with regard tothe knownmotors section. i 4 an energy-per unit of cylinder contents isat--- \:'Eig'. 2-. .--'is.ta.cross-sectionalyiew.ofzthe hot tained whichis ten or even more times higher ohamber of this motor taken on line11-11 of than that of the'known-machines. r i.

In a known machine the absence of a hot Fige-sisanother form ofconstruction of a hot- --chamber makes it necessary for theamountsofgasmotoracconding to, theinvention. medium-required for'the cycle tobehousedl in The hot-j-gasnmotor. of...the;;type. illustrated in theheater. Since this chamber must be cap- Fig. 1 is constituted by aworking cylinder comand which are destined to contain a hot and aprising inter alia the hot chamber i9 and the cold chamber which isconstituted by two sections H and I2. The section [2 has the form of acylinder jacket for the working piston iii. In the position shown thedisplacer if: has penetrated completely into the hot chamber iii so thatonly the disadvantageous space thereof, i. e. a small necessary pistonclearance between the head of the displacer l6 and the cylinder headbeside the supply channels to the heater E5, is left free.

The hot chamber iii is surround-ed by ac heater l9 which subdivides thegaseous current from the hot chamber iii. This heater comprisesapproximately a hundred axial ribs which are shot-n in section in Fig.2. In comparatively large motors this number of ribs may rise, forexample, to 250. As a matter of tact, the gaseous current may also besubdivided in numerous other manners. Between the ribs shown narrowchannels are recessed through which hows the gas to be heated. Theseribs are cast as a whole or in any case connected in goodheat-conductive manner to the wall of this heater, which directly adoinsthe heating channel it through which the required heat is supplied fromthe exterior to the heater. As previously mentioned, the gas to beheated flows in the channels between the ribs so that the gas is incontact with at least two surfaces which emit the heat to the gas andhave this heat supplied to them from the exterior, viz. from the channelit. A metal bush 2%, which exactly fits into the inner periphery ofthese ribs, prevents direct communication between the hot chamber I0 andthe heater it, so that the gas displaced by the displacer it is forcedto flow through the annular channel 23 into the heater and can leave thelatter only at the opposite end towards the regenerator 2b.

In this regencrator 2B the heated expanding gas emits part of its heatand subsequently enters into the cooler 2 l The latter, like the heaterit, contains a certain number of axial ribs between which narrowchannels are recessed. As before, the gas during the flowing through thecooler is in contact with at least two surfaces which take over the heatfrom the gas, emitting it through the wall of the cooler to the coolingjacket [5. The latter extends in addition over part l2 of the coldchamber, in which the piston moves, so that the friction surfaces of thepiston it are always maintained cool. The lubrication of this piston andthe gas-tight obturation by means of p'ston springs does not involveparticular diiiiculty at this low temperature.

The cooler 2i is also obturated from the cold chamber H by means of thecylindrical sleeve 22 which fits into the inner periphery of the ribs sothat the gaseous current from the regenerator 20 has to traverse thewhole cooler to come subsequently by means of the annular channel 2d inthe cold chambers l! and 52 above the working piston 13. The said sleeve22 is consequently located in the hot chamber opposite the heater aswell as opposite the regenerator 2i! and opposite the cooler and thecold chamber. The portion of this sleeve which is located in the hotchamber consequently attains a considerably higher temperature than theportion which is located in the cold chamber so that a constant hotcurrent will fiow through the wall of this sleeve from the hot to thecold chamber, which means a loss of heat for the circuit. In order tominimize this loss, the wall of the sleeve has a small thickness and is,in addition, made of material which retains its form at the hightemperature prevailing in the hot chamber and has a poorheat-conductivity. The material used for this purpose may be, forexample, an iron alloy containing cobalt and nickel.

The displacer It is also located in part in the hot chamber and in partin the cold chamber so that here the same remark applies as for thesleeve 22. At the operating temperature of the motor which prevails inthe hot chamber it would practically be impossible to guide thedisplacer it into 7 the sleeve 22. Consequently, the outer diameter ofthe displacer i6 is made smaller than the inner diameter of the sleeve22 to such extent that these components do not make contact duringoperation. A difierence in diameter of 0.2 mm. for small machines and upto 2 mms. for large machines suffices to this end. The guidance of thedisplacer it must be located in another portion of the motor, i. e.preferably in the cold chamber, so that the lubrication does not involvedifficulty. In the form of construction shown the displacer rod 25 isguided into the body of the piston l3.

During the operation of the motor the piston and the displacerperiodic-ally move to and iro relatively to the motor due to themovement of the rotating crank and since the cranks of the piston and ofthe displacer form an angle of 50 to the piston and the displacer alsomore relatively to one another.

In the position shown the displacer it has arrived at the end of theentering stroke, i. e., the displacer has penetrated as far as possibleinto the hot chamber. The movement preceding the position shown hasconsequently driven the gas out or the hot chamber. Since, as hasalready been mentioned above, the piston clearance between the displacerIt and the sleeve 22 is limited to a value necessary for constructionalreasons, the gas will practically be forced to flow in the direction ofthe arrows shown through the annular channel 23 to the heater l9.Therefrcm the gas expands also in the direction of the arrows shownthrough the regenerator 2!] and the cooler 28 to the cold chambers H [2.In these chambers the gas pressure increases and the piston I3 makes theoutgoing stroke.

During the movement subsequent to the position shown in Fig. 1, thedisplacer It moves again in the outgoing direction. At the end of theoutgoing stroke, the working piston It makes the entering stroke andconsequently approaches the displacer IS. The cold chamber H becomessmaller but the hot chamber Ii] becomes larger 50 that the gas is nowdisplaced in a directon opposite to that of the arrows through thecooler 2 i, the regenerator 2i) and the heater i9 to the hot chamber It.When the displacer It and the piston l3 practically engage each other,i. e., with a spacing of, say, 0.1 mm., the cold chamber has become nil.The remaining space formed by the necessary clearance between the pistonand the displacer and the space which is not covered by the piston andthe displacer, such as the annular channel 24, constitutes thedisadvantageous space.

Fig. 3 shows another form of construction of a hot-gas motor accordingto the invention. The parts such as the hot chamber, the heater, theregenerator, the cooler and the cold chamber are substantially identicalto those of the forms of construction shown in Figs. 1 and 2. Like partsare designated by the same reference numerals primed.

Inthe present. form of construction .the hot chamber ll) ispreceded byanadditional heater CZ'Hand a' 'second hot chamber 26 and further thecold chamber H is followed by another cooler 29. and subsequently by asecond cold chamber 2?.

'The heater 28 is housed in the head of the cylinder in the form of afew ribs extending in the axial direction of the cylinder with narrowchannels between them. Due to the presence of somesleeves 30 which arepushed on the edges of the ribs the gaseous current is forced totraverse these channels from the beginning to the "end according to thedirection indicated by the "arrow in Fig. 3. The second hot chamber 26is formed between the head of 'thecylinderand the cylindrical extensionI with which the displacer i6 is provided. As'are'sult of the 'movementsof the displacer, the cylindrical extension vII- penetrates intothe-additional 'h'ater 28 'so that'the 'chamber'26 is periodicallyenlarg'ed and reduced and thus satisfies the'r'equirements" which 1 ahotchamber has to satisfy. v

The second cooler is secured to the awn l3 which for this purpose iscooled artificially in known manner with the aid of air or water whichis supplied and carried off through the piston rod. This cooler is alsoconstituted-by a certain number of ribs extending in the axial directionof the cylinder and having narrow channels between them. Owing to thepresence of the sleeves 3|,

direct communication with the cold chamber is avoided so that the gaseshave to follow the-path -indicated by the arrow in Fig. 3. a

'The second cold chamber 2l is formed by a icylindrical extension lfiofthe cylinder lfiwhich penetrates into the cooler 29 andmoves out of itdueto the periodic movement'of the di'splacer l6 andof the piston l3.

[The provision of the above-sta'tedsecond heater between the two hotchambers permits ofobtaining an approximation of the isothermalexpansion in the cylinder which in itself is advantagems-for the hot-gasmotor. The "cooling which the medium undergoes as a result of the expan-"sion is compensated by the additional'heat supjpl iedito the gas in theheater 28. Similarly,the

second coolerag impr oves the isothermal'compression.

What we claim is:

'l. A closed cycle hot-gas motor comprising means defining a hotchamber, a regenerat-er,

conduit means connecting said-hot chamber-with said regenerator, aheater operatively associated with said conduit means for applying heatdirectly only to the gas in saidconduit means and forming a heater meanstherewith, said conduit means comprising means forming a multiplicity ofpaths for the passage therethrough of the gas of'said motor, meansdefining a cold chamber, sec- 0nd conduit means connecting said coldchamber 'withsaid'regenerator, and a cooler interposed between'saidregenerator andsaid cold chamber and operatively associated with saidsecond conduit means, said hotchamber, heater means,regenerator,'-cooler, and cold chamber constituting sepaa rate cycleelements of said motor, and the mini- -"mum vol-ume' of-*said'hot"chamber-being substan- 'means'defining a hot chamber, a'regene'ra'tor,

' conduit means connecting said hot chamber with said-regeneratonaheater operatively "associated with said conduit means for applyinglieat di- 8 forming a heater means therewith, said conduit meanscomprising means forming a multiplicity of paths'for the passagetherethrough of the gas of said motor, means defining a cold chamber,second conduit means connecting said cold chamber with said regeneratorand a cooler interposed between said regenerator and operativelyassociated with said second conduitmeans and said cold chamber, saidsecond conduit means comprising means forming amultiplicity of paths forthe passage therethrough of the gas of said motor, said hot chamber,heater means, regenerator, cooler, and cold chamber constitutingseparate cycle elements of said motor, and the minimumvolume of said hotchamber being'sub- 'regenerator, and a cooler interposed between saidregenerator and said cold chamberand operatively'associated with saidsecond conduit means, said heater, regenerator and cooler being ar-"ranged concentric to and surrounding the said hot chamber andthe'displacer member, said'hot 'chamberfheater means,'reg'en'erator,cooler, and

cold chamber constituting separate cycle elemhts of said motor, and theminimumvolume of said hot chamber being substantially zero asdeterminedby constructional 'clearances'of the'said displacer in the "saidhotchamber.

'4. 'A' closed cycle hot-gas motor comprising ing a second hotChamberffirstconduit means connectingsaid first'hot' chamber with saidsecchance chamber, a first heater operatively associated withsaid firstconduitm-eans for "heating 5 0 i the gas of said motor therein, saidconduit means and said'first heater comprising a first heater means,a'regenerator, second conduit means connectingsaid first hot/chamberwith said regener- "atorj a second heater operatively associated withsaid second conduit means for heating the gas of said motor therein,said second conduit means comprising means forming a multiplicity ofpaths for the passage=therethrough of the gas of said motor, said secondconduit means and said second-heatercomprising a: second heater means,meansdefining a cold-chamber, third conduit means-connecting saidregenerator with saidcold chamber, a cooler operatively associated withsaid third conduit means for cooling the gas of said motor-therein, saidcooler and-said third conduit means comprising a coolermeans, said notcha-mbers, saidheater means, said regenerator, said coo1er =means,"and-said' cold chamber constituting separate cycle elements of 'said motor;and-the 1 minimum-volume of said hot chambers being substantially zeroas determined by constructional cl'earances of' thehot chamber definingmeans. i 5;'A closed lcyclehot-gas motor comprising means defining afirst hot chamber, means defini rectly *only to the "gas-in said conduitmeans 'and 75 ing a 'se'cond 'hot chamber, first conduit meansconnecting said first hot chamber with said sec-v ond hot chamber, afirst heater operatively associated with said first conduit means forheating the gas of said motor therein; said conduit means and said firstheater comprising a first heater means, a regenerator, second conduitmeans connecting said first hot chamber with said regenerator, a secondheater operatively associated with said second conduit means for heatingthe gas of said motor therein; said second conduit means comprisingmeans forming a multiplicity of paths for the passage therethrough ofthe gas of said motor, said second conduit means and said second heatercomprising a second heater means, means defining a first cold chamber,third conduit means connecting said regenerator with said first coldchamber, a first cooler operatively associated with said third conduitmeans for cooling the gas of said motor therein; said third conduitmeans and said first cooler comprising a first cooler means, meansdefining a second cold chamber, fourth conduit means connecting saidfirst cold chamber with said second cold chamber, a second cooleroperatively associated with said fourth conduit means for cooling thegas of said motor therein, said fourth conduit means and said secondcooler means defining a second cooler means, said hot chambers, saidheater means, said regenerator, said cooler means,

and said cold chambers constituting separate means forming amultiplicity of paths for the passage therethrough of the gas of saidmotor, a reciprocating piston member defining a cold chamber, secondconduit means connecting said cold chamber with said regenerator, acooler operatively associated with said second conduit means for coolingthe gas of said motor therein; said second conduit means and said coolercomprising a cooler means, and a tubular member surrounding saiddisplacer member, said heater, regenerator and cooler surrounding saidtubular member, said hot chamber, heater means, regenerator, coolermeans, and cold chamber constituting separate cycle elements of saidmotor, and the minimum volume of said hot chamber being substantiallyzero as determined by constructional clearances of the said displacer inthe said hot chamber.

HERRE RINIA.

HEINRICH DE BREY.

FRANCISCUS LAMBERTUS VAN WEENEN. YSBRAND BOERS.

GABRIEL LEONARD SYPKENS.

WILLEM JAN VAN HEECKEREN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 11,696 Napier et a1 Sept. 19,1854 228,716 Woodbury et al June 8, 1880 389,045 Bair Sept. 4, 1888404,237 Woodbury May 28, 1889 437,320 Vivian Sept. 30, 1890 966,032 MannAug. 2, 1910 1,534,794 Lundgaard Apr. 21, 1925 FOREIGN PATENTS NumberCountry Date 26,767 Germany May 28, 1884

